a. Field of the Invention
The present invention relates to an improvement of the activated sludge process for treating waste water containing a spongy substance by aeration in an aeration tank.
B. Description of the Prior Art
The activated sludge process for treating waste water by employing a spongy substance such as foamed polyurethane, foamed polyethylene, etc. has recently been developed. Inasmuch as the activated sludge for use therein is in the form of bulky grains convenient for handling, this waste water treating process promises various advantages which cannot be expected from other conventional activated sludge processes. Nevertheless, when it comes to the question of putting it to practical use, it still involves various problems that need be solved.